Electrical power connection in an emergency park brake system

ABSTRACT

An emergency park brake system of an aircraft may include an electrical power interface, an electromechanical actuator, and a hydraulic brake valve. The electrical power interface may be configured to receive electrical power from a power source. The electromechanical actuator may be in selective power receiving communication with the electrical power interface and the electromechanical actuator may be mechanically coupled to and configured to selectively actuate the hydraulic brake valve. The electrical connection between the electromechanical actuator and the electrical power interface may be based on an emergency braking input.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of, claims priority to and the benefitof, U.S. Ser. No. 15/490,581 filed Apr. 18, 2017 and entitled“ELECTRICAL POWER CONNECTION IN AN EMERGENCY PARK BRAKE SYSTEM,” whichis incorporated herein by reference in its entirety for all purposes.

FIELD

The present disclosure relates to aircraft systems, and morespecifically, to emergency park brake systems.

BACKGROUND

Aircraft typically have brakes on the wheels to slow the aircraft duringaborted takeoffs, landings, and/or while taxiing. Additionally, someaircraft employ emergency park brake systems that execute emergencybraking and/or maintain a braking force while the aircraft is parked.Conventional brake systems generally include a mechanical linkage (e.g.,a cable) that extends between a user brake interface (e.g., a pedal or ahandle) and a braking force actuator. These conventional mechanicallinkage systems, however, can be difficult and complex to implement.While electrical configurations can be implemented to replace and solvesome of the complexities of the mechanical linkage configurations,conventional electrical configurations can be susceptible to uncommandedbraking. For example, unintentionally executed, undesired, oruncommanded braking, whether due to user error or component failure, mayresult in the application of a braking force on the wheels of anaircraft at inopportune times (e.g., during takeoff).

SUMMARY

In various embodiments, the present disclosure provides an emergencypark brake system of an aircraft. The emergency park brake system mayinclude an electrical power interface configured to receive electricalpower from a power source, an electromechanical actuator in selectivepower receiving communication with the electrical power interface, and ahydraulic brake valve, wherein the electromechanical actuator ismechanically coupled to and configured to selectively actuate thehydraulic brake valve.

In various embodiments, whether the electromechanical actuator is inpower receiving communication with the electrical power interface isbased on an emergency braking input. In various embodiments, theemergency park brake system further includes a user input interface,wherein the emergency braking input is a displacement of the user inputinterface. The emergency park brake system may include a displacementsensor coupled to the user input interface. The displacement sensor maybe configured to detect the displacement of the user input interface andgenerate an emergency braking command based on the displacement of theuser input interface. In various embodiments, the emergency park brakesystem further includes an excitation monitor coupled to thedisplacement sensor and configured to detect an excitation level of thedisplacement sensor.

In various embodiments, whether the electromechanical actuator is inpower receiving communication with the electrical power interface isbased on the emergency braking command and the excitation level of thedisplacement sensor. In various embodiments, the electromechanicalactuator is electrically disconnected from the electrical powerinterface in response to the displacement of the user input interfacebeing less than a threshold displacement.

Also disclosed herein, according to various embodiments, is an emergencypark brake system of an aircraft. The emergency park brake system mayinclude an electrical power interface configured to receive electricalpower from a power source, an electromechanical actuator in selectivepower receiving communication with the electrical power interface, and ahydraulic brake valve, wherein the electromechanical actuator ismechanically coupled to and configured to selectively actuate thehydraulic brake valve. The emergency park brake system may furtherinclude a plurality of discrete hardware controllers interconnected viaa first electrical communication pathway and a second electricalcommunication pathway, wherein the plurality of discrete hardwarecontrollers have instructions stored thereon that cause the emergencypark brake system to perform various operations. The various operationsinclude receiving an emergency braking input, determining an emergencybraking command based on the emergency braking input, determining apower supply condition based on the emergency braking command,transmitting, via the first electrical communication pathway, theemergency braking command to the electromechanical actuator, andtransmitting, based on the power supply condition and via the secondelectrical communication pathway, electrical power from the electricalpower interface to the electromechanical actuator.

In various embodiments, the emergency park brake system further includesa user input interface, wherein the emergency braking input is adisplacement of the user input interface. The emergency park brakesystem may further include a displacement sensor coupled to the userinput interface. The displacement sensor may be configured to detect thedisplacement of the user input interface and generate the emergencybraking command based on the displacement of the user input interface.In various embodiments, whether the electromechanical actuator is inpower receiving communication with the electrical power interface isbased on the emergency braking command.

In various embodiments, the emergency park brake system further includesan excitation monitor coupled to the displacement sensor and configuredto detect an excitation level of the displacement sensor. In variousembodiments, whether the electromechanical actuator is in powerreceiving communication with the electrical power interface is based onthe emergency braking command and the excitation level of thedisplacement sensor. In various embodiments, the power supply conditionis based on the excitation level of the displacement sensor.

In various embodiments, determining the emergency braking commandcomprises comparing the displacement of the user input interface with athreshold displacement. In various embodiments, the power supplycondition indicates a power disconnection in response to thedisplacement of the user input interface being less than the thresholddisplacement. In various embodiments, the power supply conditionindicates a power connection in response to the displacement of the userinput interface being greater than the threshold displacement.

Also disclosed herein, according to various embodiments, is a method ofcontrolling an emergency park brake system of an aircraft. The methodmay include receiving, by an emergency park brake controller, anemergency braking input. The method may also include determining, by afirst electrical communication pathway of the emergency park brakecontroller, a power connection command based on the emergency brakinginput. The method may also include determining, by a second electricalcommunication pathway of the emergency park brake controller, anemergency braking command based on the emergency braking input. Themethod may further include actuating, by the emergency park brakecontroller, via an electromechanical actuator, and based on the powerconnection command and the emergency braking command, a hydraulic brakevalve.

In various embodiments, actuating the hydraulic brake valve to apply abraking force to wheels of the aircraft is performed in response to thepower connection command indicating a power supply condition thatindicates a power connection. In various embodiments, actuating thehydraulic brake valve includes transmitting, by the emergency park brakecontroller and via the first electrical communication pathway, the powerconnection command to the electromechanical actuator. In variousembodiments, actuating the hydraulic brake valve includes transmitting,by the emergency park brake controller, based on the power supplycondition, and via the second electrical communication pathway, theemergency braking command to the electromechanical actuator.

The forgoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated hereinotherwise. These features and elements as well as the operation of thedisclosed embodiments will become more apparent in light of thefollowing description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an exemplary aircraft having an emergency park brakesystem, in accordance with various embodiments;

FIG. 1B illustrates a cross-sectional view of a brake assembly, inaccordance with various embodiments;

FIGS. 2A, 2B and 2C illustrate schematics of an emergency park brakesystem, in accordance with various embodiments; and

FIG. 3 is a schematic flow chart diagram of a method of controlling anemergency park brake system, in accordance with various embodiments.

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the drawing figures, wherein like numeralsdenote like elements.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes referenceto the accompanying drawings, which show exemplary embodiments by way ofillustration. While these exemplary embodiments are described insufficient detail to enable those skilled in the art to practice thedisclosure, it should be understood that other embodiments may berealized and that logical changes and adaptations in design andconstruction may be made in accordance with this disclosure and theteachings herein without departing from the spirit and scope of thedisclosure. Thus, the detailed description herein is presented forpurposes of illustration only and not of limitation.

Referring now to FIG. 1A, in accordance with various embodiments, anaircraft 10 may include landing gear such as main landing gear 12, mainlanding gear 14 and nose landing gear 16. Main landing gear 12, mainlanding gear 14, and nose landing gear 16 may generally support aircraft10 when aircraft 10 is not flying, allowing aircraft 10 to taxi, takeoff and land without damage. Main landing gear 12 may include wheel 13Aand wheel 13B coupled by an axle 20. Main landing gear 14 may includewheel 15A and wheel 15B coupled by an axle 22. Nose landing gear 16 mayinclude nose wheel 17A and nose wheel 17B coupled by an axle 24. Invarious embodiments, aircraft 10 may comprise any number of landinggears and each landing gear may comprise any number of wheels. Mainlanding gear 12, main landing gear 14, and nose landing gear 16 may eachbe retracted for flight.

Aircraft 10 may also include a primary brake system, which may beapplied to a wheel of a landing gear. The primary brake system ofaircraft 10 may comprise a collection of subsystems that produce outputsignals for controlling the braking force and/or torque applied at eachwheel (e.g., wheel 13A, wheel 13B, wheel 15A, wheel 15B, etc.). Theprimary brake system may communicate with the brakes of each landinggear (e.g., main landing gear 12, main landing gear 14, and/or noselanding gear 16), and each brake may be mounted to each wheel to applyand release braking force on one or more wheels (e.g., as describedabove). The brakes of an aircraft 10 may include a non-rotatable wheelsupport, a wheel (e.g., wheel 13A, wheel 13B, wheel 15A, wheel 15B,wheel 17A, and/or wheel 17B) mounted to the wheel support for rotation,and a brake disk stack.

Referring to FIG. 1B, brake assembly 110 may be found on an aircraft, inaccordance with various embodiments. Brake assembly 110 may, forexample, comprise a bogie axle 112, a wheel 114 including a hub 116 anda wheel well 118, a web 120, a torque take-out assembly 122, one or moretorque bars 124, a wheel rotational axis 126, a wheel well recess 128,an actuator 130, multiple brake rotors 32, multiple brake stators 34, apressure plate 36, an end plate 38, a heat shield 140, multiple heatshield sections 142, multiple heat shield carriers 144, an air gap 146,multiple torque bar bolts 148, a torque bar pin 151, a wheel web hole152, multiple heat shield fasteners 153, multiple rotor lugs 154, andmultiple stator slots 156.

Brake disks (e.g., interleaved rotors 32 and stators 34) are disposed inwheel well recess 128 of wheel well 118. Rotors 32 are secured to torquebars 124 for rotation with wheel 114, while stators 34 are engaged withtorque take-out assembly 122. At least one actuator 130 is operable tocompress interleaved rotors 32 and stators 34 for stopping the aircraft.In this example, actuator 130 is shown as a hydraulically actuatedpiston. Pressure plate 36 and end plate 38 are disposed at opposite endsof the interleaved rotors 32 and stators 34. Rotors 32 and stators 34can comprise any material suitable for friction disks, includingceramics or carbon materials, such as a carbon/carbon composite.

Through compression of interleaved rotors 32 and stators 34 betweenpressure plates 36 and end plate 38, the resulting frictional contactslows, stops, and/or prevents rotation of wheel 114. Torque take-outassembly 122 is secured to a stationary portion of the landing geartruck such as a bogie beam or other landing gear strut, such that torquetake-out assembly 122 and stators 34 are prevented from rotating duringbraking of the aircraft.

In various embodiments, and with reference to FIG. 2A, aircraft 10 mayalso include one or more emergency park brake systems 100. The emergencypark brake systems 100 of aircraft 10 may include an electrical powerinterface 119, an electromechanical actuator 130, and a hydraulic brakevalve 132. The hydraulic brake valve 132 may be coupled to one or morewheels 213 of the aircraft 10.

As described in greater detail below, the emergency park brake system100 generally controls an emergency or parking braking force/torque thatis applied and implemented via a brake assembly (e.g., hydraulic brakevalve 132) to each wheel 213, according to various embodiments. Theemergency park brake system 100 may be separate from, for example, aprimary brake system. In various embodiments, various components of theemergency park brake system 100, such as the wheel/brake assembly 213,may be shared with a primary brake system while various other componentsof the emergency park brake system 100, such as hydraulic brake valve132 or an emergency park brake controller 220 described below withreference to FIG. 2B, are not shared with the primary brake system.

The hydraulic brake valve 132, according to various embodiments, isactuated via the electromechanical actuator 130. Said differently, theelectromechanical actuator 130 may be mechanically coupled to thehydraulic brake valve 132 and may supplant/replace the cable that wouldbe utilized in a conventional hydraulic configuration. For example, thebrake system 100 may receive an emergency braking input and theelectromechanical actuator 130 may actuate the hydraulic brake valve 132that controls the fluid pressure in the hydraulic brake valve 132.

In various embodiments, the electrical power interface 119 is configuredto receive electrical power from a power source and theelectromechanical actuator 130 may be in selective power receivingcommunication with the electrical power interface 119, as indicated bydashed line 125. Said differently, the electromechanical actuator 130 isnot always connected to the power source via the electrical powerinterface 119, according to various embodiments. For example, in orderto prevent inadvertent or uncommanded braking, the electromechanicalactuator 130 may be electrically disconnected from the electrical powerinterface 119 unless a power supply condition is satisfied. In responseto the power supply condition being satisfied or in response to thepower supply condition indicating a powered connection, the electricalpower interface 119 may be electrically connected to theelectromechanical actuator 130 and the electromechanical actuator 130may control braking force applied to the wheels 213 via selectiveactuation of the hydraulic brake valve 132 based on a determined brakingcommand (as described in greater detail below).

In various embodiments, and with reference to FIG. 2B, the emergencypark brake system 200 may also include an emergency park brakecontroller 220. The emergency park brake controller 220 is generallyconfigured to receive an emergency braking input (or park brakinginput), determine an emergency braking command based on the emergencybraking input, and determine the power supply condition, according tovarious embodiments and as described in greater detail below. Theemergency park brake controller 220, according to various embodiments,is separate from computer systems onboard aircraft 10 such as, forexample, a brake control unit (BCU), a full authority digital enginecontrol (FADEC), an engine-indicating and crew-alerting system (EICAS),and/or the like. The emergency park brake controller 220 may be acomponent of the electromechanical actuator or may be a standalonecomputer system separate from overall control system of the aircraft 10.The emergency park brake controller 220 may include one or moreprocessors and/or one or more tangible, non-transitory memories and becapable of implementing logic. Each processor can be a general purposeprocessor, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof.

In various embodiments, the processor of the emergency park brakecontroller 220 may be configured to implement various logical operationsin response to execution of instructions, for example, instructionsstored on the non-transitory memory (e.g., tangible, computer-readablemedium). As used herein, the term “non-transitory” is to be understoodto remove only propagating transitory signals per se from the claimscope and does not relinquish rights to all standard computer-readablemedia that are not only propagating transitory signals per se. Statedanother way, the meaning of the term “non-transitory computer-readablemedium” and “non-transitory computer-readable storage medium” should beconstrued to exclude only those types of transitory computer-readablemedia which were found in In Re Nuijten to fall outside the scope ofpatentable subject matter under 35 U.S.C. § 101.

In various embodiments, the term “emergency park brake controller 220”refers to a plurality of discrete hardware controllers interconnectedvia a first electrical communication pathway and a second electricalcommunication pathway. The plurality of discrete hardware controllersmay have instructions stored thereon that cause the emergency park brakesystem to perform the operations described below.

In various embodiments, and with continued reference to FIG. 2B, theemergency park brake controller 220 may receive an emergency brakinginput via user displacement of a pedal or a handle, as described ingreater detail below with reference to FIG. 2C. The emergency park brakecontroller 220 generates an emergency braking command based on theemergency braking input, according to various embodiments. The emergencypark brake controller 220 also generates a power supply condition thatis based on the emergency braking command, according to variousembodiments. As mentioned above, the power supply condition may indicatea “power disconnection” between the electrical power interface 119 andthe electromechanical actuator 130 or the power supply condition mayindicate a “power connection” between the electrical power interface 119and the electromechanical actuator 130.

In various embodiments, the emergency park brake controller 220 includesa first electrical communication pathway 224 and a second electricalcommunication pathway 225. The emergency park brake controller 220 maysend a power connection command via the first electrical communicationpathway 224 to the electrical power interface 119. The power connectiondemand may indicate whether the selective electrical connection 125between electrical power interface and the electromechanical actuator130 is to be electrically connected or electrically disconnected. Theemergency park brake controller 220 may send the emergency brakingcommand to the electromechanical actuator 130 via the second electricalcommunication pathway 225. The two separate electrical communicationpathways 224, 225 provide a degree of redundancy to ensure that abraking force is intended and desired to be applied to the wheels 213.Said differently, and according to various embodiments, theelectromechanical actuator 130 only actuates the hydraulic brake valve132 to effectuate a braking force on the wheels 213 in response to thepower supply condition being satisfied (e.g. indicating a powerconnection) and in response to the generated emergency braking commandcalling for application of braking force.

In various embodiments, and with reference to FIG. 2C, the emergencypark brake system 300 further includes a user input interface 305 and adisplacement sensor 310. In various embodiments, the emergency brakinginput may be received in the form of a displacement of the user inputinterface 305. The user input interface 305 of the emergency park brakesystem 300 is configured to receive actuation/input from a user. Forexample, the user input interface 305 may be an emergency brake handle,level, or other movable mechanical component, that is integrated withina cockpit of the aircraft 10. In various embodiments, the user inputinterface 305 is separate from the cockpit. In various embodiments, theuser input interface 305 may be a remote lever or other user interfacethat is suitable for being actuated by a remote user (e.g., unmannedaircraft). The displacement sensor 310, according to variousembodiments, is coupled to the user input interface 305 and isconfigured to detect displacement of the user input interface 305 from aneutral or “zero” position and communicate the detected displacement tothe emergency park brake controller 220.

The displacement sensor 310 may include any suitable sensor, such as,for example, a linear variable differential transformer (LVDT), a rotaryvariable differential transformer (RVDT), a potentiometer, a magneticencoder, and/or the like. The displacement sensor 310 may generate andtransmit the detected displacement as a variable brake signal (e.g.,representative of a percentage of displacement of the user inputinterface 305 from a zero, reference position to a maximum referenceposition).

In various embodiments, the emergency park brake controller 220 isconfigured to generate the emergency braking by comparing the detecteddisplacement with a predetermined threshold displacement. The thresholddisplacement may refer to a predetermined minimum displacement value(e.g., a “deadband” threshold). For example, if the detecteddisplacement of the user input interface 305 is less than the thresholddisplacement, the emergency braking command generated by the emergencypark brake controller 220 may indicate a null demand/command. That is,if the user input interface 305 has not been actuated or if the userinput interface 305 is not sufficiently actuated (displaced), a signalindicating “no braking” may be sent by the emergency park brakecontroller 220 to the electromechanical actuator 130, according tovarious embodiments. However, if the user input interface 305 issufficiently actuated (displaced) beyond the threshold displacement, theemergency braking command indicates a braking force to be actuated andthus a signal indicating “braking” is sent to the electromechanicalactuator 130.

In various embodiments, the threshold displacement is about 20% from azero position of the user input interface 305 to a maximum displacementposition of the user input interface 305. In various embodiments, thethreshold displacement is about 15% from a zero position of the userinput interface 305 to a maximum displacement position of the user inputinterface 305. In various embodiments, the threshold displacement isabout 10% from a zero position of the user input interface 305 to amaximum displacement position of the user input interface 305. As usedin the instant context, the term “about” refers to plus or minus 1.0%.In various embodiments, the power supply condition is dependent on theemergency braking command. For example, if the emergency braking commandindicates “no braking,” the power supply condition generated andtransmitted by the emergency park brake controller via the firstelectrical communication pathway 224 may indicate “power disconnection.”

In various embodiments, the emergency park brake system 300 furtherincludes one or more excitation monitors 311 that are coupled to thedisplacement sensor(s) 310. The excitation monitor 311 is configured toprovide electrical power to the displacement sensor 310 so that thedisplacement position can be provided to the emergency park brakecontroller 220. The excitation level of the displacement sensor 310 maybe, for example, in the form of a sine wave having a frequency of 2500Hertz and a voltage of 3.5 V (root mean squared voltage). In variousembodiments, whether the electromechanical actuator 130 is in powerreceiving communication with the electrical power interface 119 is basedon the detected valid excitation level of the displacement sensor 310(e.g., the excitation monitor 311 checks the validity of the excitationlevel of the displacement sensor 310). For example, if the excitationlevel provided from the excitation monitor 311 to the displacementsensor 310 is invalid (e.g., the displacement sensor is not detecting adisplacement of the user input interface 305), the power supplycondition may indicate “power disconnection” and the selectiveelectrical connection 125 between the electromechanical actuator 130 andthe electrical power interface 119 may be electrically disconnected.

In various embodiments, the emergency park brake system 300 may includeother detectors, sensors, or components that check various operatingparameters to verify that a braking command is intended. For example,the emergency park brake system 300 may include multiple user inputinterfaces, such as an inboard and an outboard handle/lever. In variousembodiments, the emergency park brake system 300 may include multipledisplacement sensors. If one of the operating parameters does not meet agiven threshold, the emergency park brake controller 220 may generate apower supply condition that indicates “power disconnection” or no powerdelivery to the electromechanical actuator 130. If all the operatingparameters meet the given thresholds, the emergency park brakecontroller 220 may generate a power supply condition that indicates“power connection” and thus the electromechanical actuator 130 may beelectorally powered.

In various embodiments, and with reference to FIG. 3 , a method 390 ofcontrolling an emergency park brake system is provided. The method 390may include receiving an emergency braking input at step 392. Forexample, an emergency park brake controller may receive the emergencybraking input via a displacement sensor coupled to a user inputinterface (e.g., a brake handle). The method 390 may further includedetermining an emergency braking command at step 394. In variousembodiments, the emergency park brake controller generates the emergencybraking command based on the emergency braking input. Still further, themethod 390 may include determining, by the emergency park brakecontroller, a power supply condition at step 396. Determining the powersupply condition (step 396) may be based on the emergency brakingcommand determined at step 394. In various embodiments, the method 390further includes actuating a hydraulic brake valve at step 398. Step 398may be performed by the emergency park brake controller, via anelectromechanical actuator, and based on the emergency braking commandand the power supply condition determined in steps 394 and 396,respectively.

In various embodiments, actuating the hydraulic brake valve to apply abraking force (step 398) to wheels of the aircraft is performed inresponse to the power supply condition indicating a power connection. Invarious embodiments, step 398 includes transmitting, by the emergencypark brake controller and via a first electrical communication pathway,the emergency braking command to the electromechanical actuator. Step398 may also include transmitting, by the emergency park brakecontroller, based on the power supply condition, and via a secondelectrical communication pathway, electrical power from an electricalpower interface to the electromechanical actuator.

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of the disclosure.

The scope of the disclosure is accordingly to be limited by nothingother than the appended claims, in which reference to an element in thesingular is not intended to mean “one and only one” unless explicitly sostated, but rather “one or more.” It is to be understood that unlessspecifically stated otherwise, references to “a,” “an,” and/or “the” mayinclude one or more than one and that reference to an item in thesingular may also include the item in the plural. All ranges and ratiolimits disclosed herein may be combined.

Moreover, where a phrase similar to “at least one of A, B, and C” isused in the claims, it is intended that the phrase be interpreted tomean that A alone may be present in an embodiment, B alone may bepresent in an embodiment, C alone may be present in an embodiment, orthat any combination of the elements A, B and C may be present in asingle embodiment; for example, A and B, A and C, B and C, or A and Band C.

Also, any reference to attached, fixed, connected, coupled or the likemay include permanent (e.g., integral), removable, temporary, partial,full, and/or any other possible attachment option. Differentcross-hatching is used throughout the figures to denote different partsbut not necessarily to denote the same or different materials.

The steps recited in any of the method or process descriptions may beexecuted in any order and are not necessarily limited to the orderpresented. Furthermore, any reference to singular includes pluralembodiments, and any reference to more than one component or step mayinclude a singular embodiment or step. Elements and steps in the figuresare illustrated for simplicity and clarity and have not necessarily beenrendered according to any particular sequence. For example, steps thatmay be performed concurrently or in different order are illustrated inthe figures to help to improve understanding of embodiments of thepresent disclosure.

Any reference to attached, fixed, connected or the like may includepermanent, removable, temporary, partial, full and/or any other possibleattachment option. Additionally, any reference to without contact (orsimilar phrases) may also include reduced contact or minimal contact.Surface shading lines may be used throughout the figures to denotedifferent parts or areas but not necessarily to denote the same ordifferent materials. In some cases, reference coordinates may bespecific to each figure.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “one embodiment”, “an embodiment”,“various embodiments”, etc., indicate that the embodiment described mayinclude a particular feature, structure, or characteristic, but everyembodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed. After reading the description, it will be apparent to oneskilled in the relevant art(s) how to implement the disclosure inalternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element is intended to invoke 35 U.S.C. 112(f)unless the element is expressly recited using the phrase “means for.” Asused herein, the terms “comprises”, “comprising”, or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus.

What is claimed is:
 1. An emergency park brake system of an aircraft,the emergency park brake system comprising: an electrical powerinterface configured to receive electrical power from a power source; anelectromechanical actuator coupled to the electrical power interface viaa selective electrical connection; a hydraulic brake valve, wherein theelectromechanical actuator is mechanically coupled to and configured toselectively actuate the hydraulic brake valve; and a plurality ofdiscrete hardware controllers interconnected via a first electricalcommunication pathway and a second electrical communication pathway,wherein the plurality of discrete hardware controllers have instructionsstored thereon that cause the emergency park brake system to performoperations comprising: receiving an emergency braking input; determininga power connection command based on the emergency braking input;determining an emergency braking command based on the emergency brakinginput; transmitting, via the first electrical communication pathway, thepower connection command to the electrical power interface;transmitting, via the second electrical communication pathway, theemergency braking command to the electromechanical actuator; determininga power supply condition, based on the power connection command; andtransmitting, based on the power supply condition and via the selectiveelectrical connection, electrical power from the electrical powerinterface to the electromechanical actuator.
 2. The emergency park brakesystem of claim 1, further comprising a user input interface, whereinthe emergency braking input is a displacement of the user inputinterface.
 3. The emergency park brake system of claim 2, furthercomprising a displacement sensor coupled to the user input interface,wherein the displacement sensor is configured to detect the displacementof the user input interface and generate the emergency braking commandbased on the displacement of the user input interface.
 4. The emergencypark brake system of claim 3, wherein whether the electromechanicalactuator is in power receiving communication with the electrical powerinterface is based on the emergency braking command.
 5. The emergencypark brake system of claim 4, further comprising an excitation monitorcoupled to the displacement sensor and configured to detect a validityof an excitation level of the displacement sensor.
 6. The emergency parkbrake system of claim 5, wherein whether the electromechanical actuatoris in power receiving communication with the electrical power interfaceis based on the emergency braking command and the validity of theexcitation level of the displacement sensor.
 7. The emergency park brakesystem of claim 5, wherein the power supply condition is based on thevalidity of the excitation level of the displacement sensor.
 8. Theemergency park brake system of claim 3, wherein determining theemergency braking command comprises comparing the displacement of theuser input interface with a threshold displacement.
 9. The emergencypark brake system of claim 8, wherein the power supply conditionindicates a power disconnection in response to the displacement of theuser input interface being less than the threshold displacement.
 10. Theemergency park brake system of claim 8, wherein the power supplycondition indicates a power connection in response to the displacementof the user input interface being greater than the thresholddisplacement.
 11. A method of controlling an emergency park brake systemof an aircraft, the method comprising: receiving, by an emergency parkbrake controller, an emergency braking input; determining, by a firstelectrical communication pathway of the emergency park brake controller,a power connection command based on the emergency braking input;determining, by a second electrical communication pathway of theemergency park brake controller, an emergency braking command based onthe emergency braking input; and actuating, by the emergency park brakecontroller, via an electromechanical actuator, and based on the powerconnection command and the emergency braking command, a hydraulic brakevalve.
 12. The method of claim 11, wherein actuating the hydraulic brakevalve to apply a braking force to wheels of the aircraft is performed inresponse to the power connection command comprising a power supplycondition that indicates a power connection.
 13. The method of claim 11,wherein actuating the hydraulic brake valve comprises: transmitting, bythe emergency park brake controller, based on the power connectioncommand, and via the first electrical communication pathway, electricalpower from an electrical power interface to the electromechanicalactuator; and transmitting, by the emergency park brake controller andvia the second electrical communication pathway, the emergency brakingcommand to the electromechanical actuator.